Several questions: Was there any degree of light with the old panel? Did you make sure to install the new panel with the correct side facing out? Do you have the 2006 with the on/off switch? Is the new panel a direct fit, or did it need to be cut? It's also possible that the inverter has failed. I replaced my EL panel maybe 3 years ago, and the replacement does not provide a level of brightness that it should.